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Posted: 1/25/2014 8:51:52 AM EDT
My Rainier Arms Evolution rail just came in. While installing it i noticed that the rail wasn't slipping over the thermal bushing. I took my dial calipers out and took a few measurements and sure enough....The thermal bushing had a larger OD than the hand guard's ID.  I gave Rainier Arms a call and the tech support guy thought that I was installing incorrectly, he then gave Samson MFG a call and come to find out there was a problem with some thermal bushing quality control, obviously. The tech put me on a list to have the new bushings mailed out to me. I just wanted to let anyone know if you're having problems installing an Evolution rail, DO NOT force or hammer the hand guard on.
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| Wow, really glad I saw this thread. Been dealing with this for a couple weeks on a new build. Ordered 7'' rail and it would NOT slide over bushing. Decided not to muscle it on. Called Rainier and talked with Mike, great customer service BTW, and we decided to try the 9'' rail. I guess the thought was I had an out of spec rail and bushing. So, last night I try to install the 9'' rail, same result. WILL NOT slide over bushing. I will call Rainier tomorrow and request new bushings. Hopefully, this will be resolved, otherwise will have to order diff rail. |
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Okay guys. After a couple of weeks, I finally received the new bushings. The new bushings allowed the handguard to slip on about 1/8th of an inch by hand, I had to lightly hammer the handguard on with a rubber mallet. It is still a very tight fit. Also, I felt like I had to over torque the two screws to keep the handguard from wobbling. I do not like putting that much torque on heli-coils. Although the rail is on, I might not use a Evolution handguard on any future builds. I know this is not Rainier Arm's fault, 100% Samson Manufacturing's fault, they were very helpful and courteous. If anyone has a question feel free to PM me.
Good Luck |
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Got my new bushings today, just tried installing and it still really doesn't wanna go on. Not at all.
http://www.youtube.com/watch?v=XwIBJQo4qeA This video shows it sliding over with little to no effort. I'm not sure what the deal is, but it's NOT HAPPENING. I'm not a happy camper at all. Guess I'll call Rainier tomorrow. Ugh. |
| FWIW, has anyone tried putting the bushing in the freezer overnight - or ideally packing it in a bag of dry ice for an hour or two. We used to do this when we need to fit race bearings and liners when we wanted a tight fit. Thermal contraction would allow us to slide the part in and thermal expansion as it warmed up created a fit tight enough to rival any amount of Loctite. |
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No luck with the freezer. Couldn't find my heat gun and don't own a hair dryer, so I didn't heat the rail. I put the bushings in the rail, resting on the bottom in the first groove, and took a short video of their fitment. It's like the "C" shape is sprung too far out and needs to be, crimped, for lack of a better word, to make the ends a hair closer together. The video is uploading to youtube now. I'll post it when it's done.
EDIT: https://www.youtube.com/watch?v=TlMOVmFTyLs |
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Quoted:
My Rainier Arms Evolution rail just came in. While installing it i noticed that the rail wasn't slipping over the thermal bushing. I took my dial calipers out and took a few measurements and sure enough....The thermal bushing had a larger OD than the hand guard's ID. I gave Rainier Arms a call and the tech support guy thought that I was installing incorrectly, he then gave Samson MFG a call and come to find out there was a problem with some thermal bushing quality control, obviously. The tech put me on a list to have the new bushings mailed out to me. I just wanted to let anyone know if you're having problems installing an Evolution rail, DO NOT force or hammer the hand guard on.
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| Mine was super tight at first...I had to lightly tap the rail onto the bushings. I noticed that the bushings did not fit quite right around the barrel nut and required a bit of forcing to almost snap into place. After installing the hand guard a couple times...fits like a glove. Good luck. |
| I have a couple of those on my rifles and they are a tight fit. the way the bushings fit onto the nut leaves very little room for error, so check all around the barrel nut for a flaw that might keep the bushing from seating properly on the nut. it is an interference fit to get the bushing close to seating, and once the bushing is completely seated there is just a tiny bit of freeplay. once the screws are tightened the tube is quite secure and properly aligned. if the FF tube gets out of alignment while tightening, the bushings are not seated properly on the nut, or the nut has some kind of flaw which misaligns the bushing , which in turn causes the tube to get out of proper alignment. if someone has removed the barrel nut with a poorly fitting wrench they may have also damaged the nut in the gas tube notches, which will also cause a misalignment, or in a severe case, failure to allow the tube to slip over the bushings. take a very close look at the barrel nut, especially in the gas tube notches, it must be perfect. |
| I have installed three of these, and they do not go on easy. The thermal bushing has to be perfectly installed or else the grooves in the forearm and teeth on the bushing don't jibe. I know it can seem impossible, but sometimes taking the bushing off and on then having a couple of beers it will magically go on. Make sure the bushings are not upside down, they require proper orientation. |
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Ya'll are putting the bushings on correctly, right? There is a top and a bottom. See this thread:
http://www.ar15.com/forums/t_2_185/239051_Issue_with_Evo_Rail.html |
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I realize there is a top and a bottom, I'm not an idiot. I even tried the bushings in the rail with nothing on the gun. Placed in the end of the rail, it took more than a 'light tap' to even attempt to get it started going into the end of the rail, and it wouldn't go. After pulling it out, it had actually shaved a tiny bit of aluminum off of a couple of the ribs that run lengthwise down the inside of the rail.
Another video coming soon. I took one half of the bushing, and tapped it in as far as it wants to go, which is enough to hold it in place, and see that either the bushings, or the rail, are out of spec, and now the rail is getting beat up from trying to tap it in. This sucks. So frustrated. EDIT https://www.youtube.com/watch?v=Zx36p9G7Zms |
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Hi all,
Guessing this is where my first post on here will be...but I'm in the same boat as the rest of you who are working on this issue with this guard. I really like this guard, but I'm having the same issue that the rest of you are having. The bushings don't even fit into the guard properly even when the bushings aren't on the rifle. Yes, something is out of spec. What I've learned is this: I called Rainier and they were super helpful and wanted to know if I was ready to return it. Told them I'd seen online that some bushings might be out and they sent me new ones the same day. Same problem and the measurement was identical to the thousandth of an inch. I then thought well, it has Samson's name on it so I'll send them a message. They have been very quick to respond to me and the problem is not the bushing according to them, it's the extrusion process in making the clamp ears near the back. Apparently as they are extruding they are occasionally getting off at the back of the guard by a few thousandths and that is enough to create this interference issue. I'm guessing by his knowledge that this isn't the first time they've had a batch with this issue. I was told to just wrap tape and use a screwdriver to widen the gap and that fixes it...but considering as others and myself have mentioned, that isn't possible to do to fix it in my opinion and I marred the clamp ears when trying to do so. Not when with the guard and bushings alone that a single bushing still gets stuck in the back of the guard. Samson offered to exchange for one of their other guards, but mentioned that if I wanted the Rainier cut I had to go back through them. Their willingness to help is great and wonderful from both companies, I just wish the QC people had checked the guard/bushing fit....but if this is truly the first time it's happened, it may not have been an issue before. I won't hold it against them, but hopefully they'll check occasionally in the future and save them and us time and energy. Anyway, I'm not entirely sure what yet to do myself. I really like this Rainier guard, the looks, the weight and the fact it uses the stock barrel nut. But in having to use force to get it on and off is a bit more than I am comfortable with if I needed to clean it after training in the rain/mud (got it all muddy just before I got the guard during a class). Not entirely sure...with a little oil I could tap on the guard and it's not coming off...even without the screws in it. But maybe it's time to consider something else? Or do I wait and see what happens when the next batch comes in??? |
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Guys go to Samson Mfg in the Industry section. There was a thread there that was about the same thing.
It also says bushing will not fit in the rail by themselves. I'll get the link. Here check this out |
| Thanks....most interesting link and the link from that thread as well. Seems like they are designed to be fairly tight fitting over the bushings on the gun. Mayhaps I'll keep it then and within a few more on/off cycles when it needs cleaning under there, it will be fitting like a glove. |
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